Cobogó is the name of the hollow elements, originally made of concrete or ceramic, created in the 20th Century. Its name derives from the initials of the surnames of three engineers that worked in Recife, Brazil: Amadeu Oliveira Coimbra, Ernest August Boeckmann and Antônio de Góes. These elements follow the same principle of the old wooden elements of Moorish architecture: solution to the closure of structures. While looking for references to fabricate a 3D printed brick, it was natural to end up looking for elements that were already used in architecture. The hollow sections found in cobogós were perfect to spare material without compromising the stability of the structure. Re fabricate old elements paying an homage to our own backgrounds while having the chance to give it a twist. A trip in space and time.
To create the brick, we chose 5 different decoration patterns of cobogós. We constructed five solids with dimensions 21.67×21.67x2mm. For all of them we did an offset of 2mm to keep the boundaries required for the material not to break. Then we drew polylines to create the designs or rectangles. After a polyline was done, we did Extrude Closed Planar Curve with the same thickness of the original solid. With that we could erase the internal curves to avoid having unneeded geometry on the surface. Then we did Boolean Difference between the bigger solid and the ones created with the Extrusion of the Curves to make them hollow as a cobogó.
Finally we categorized each cobogó as different layers and copied and alternated them to construct the mosaic pattern. After the first wall containing 6 bricks on the x-axis and 3 on the z-axis, we used Boolean Union to create a single solid. Then we deselected all Snaps, leaving only End and then starting constructing the remaining surfaces. Copy the first wall and then rotate it on the same edge. At the end with the 4 walls created, we joined them by using Boolean Union. The same process was done to create the top surface. Once it was positioned, we did a cylinder at the center of the connections with a radius of 19.5mm and thickness of 2mm. By doing a Boolean Split between the cylinder and the top surface, we were able to split them and delete the internal parts that weren’t necessary.
After that we extruded the cylinder to its entire height required, mirrored it for the other side of the brick and Boolean Union these elements to create the top surface. Afterwards we copied by the end point to create the base and finish all sides of the brick. The caps of the cylinders of the top, as well as the cylinder of the bottom, were left open in order to use less material and try to make the brick cheaper. Finally to close the brick we used Boolean Union for all the elements to join.
After the brick was a solid, we verified the edges using the Edges tool to make sure there were no naked edges.
After that, we made a Box with the dimensions of the Cage, and choose Analyze> Mass Properties> Volume Centroid to be able to find the midpoint of the area. Choose CageEdit>Select the Bench>BoundingBox> x=4, y=10, z=4 and grabbed the 4 centered points of the brick to Scale them with the Origin point based on the Volume Centroid drawn before towards the Center of the volume.
With that, what was a straight wall became a curved structure, that could only be constructed with new technologies, such as 3D printing. The old and the new – as always – walking together.